The Jets yesterday officially announced more than half of Al Groh’s assistant coaching staff, leaving their defensive staff still uncertain.

As expected, Dan Henning was named offensive coordinator. Henning was Bill Parcells’ quarterbacks coach the last two seasons.

Also, it was announced that Bill Muir was retained as the OL coach, William Roberts will stay on to help Muir, Mike Sweatman will remain the special teams coach and Todd Haley will stay as the WRs coach despite being demoted during this past season.

With Ken Whisenhunt hired as the new TEs coach, Pat Hodgson has been reassigned as an offensive assistant for planning and research, doing computer work to pick up trends of opposing teams. Whisenhunt was drafted by Henning in Atlanta and coached by Groh there.

Perhaps the most intriguing of the moves involves Maurice Carthon, who’ll continue to be in charge of the running backs and also have added responsibility as the assistant head coach.

“On the sidelines, we’re going to miss Bill Parcells and the way he needles some players and pushes some buttons,” Henning said. “[Carthon] will be handling that as an assistant head coach, keeping players on the sidelines from getting too high and getting too low.”

It remains uncertain whether Henning or Groh will call the plays, which Parcells did. Henning said the Jets have “at least 19 critical players back on the offensive team,” which he said leaves him confident about improving upon the last two seasons.

As for the Jets’ defensive staff, it’s still unclear in several areas. Former Giants’ and Redskins’ defensive coordinator Mike Nolan has interviewed with Groh and was scheduled late yesterday or today to speak with Dan Reeves, his former head coach, about a defensive backs position in Atlanta.

The Jets have not yet officially contacted Ray Hamilton about their defensive line coach opening, but he told The Post last night, “you can definitely characterize me as interested” in coming back to the Jets, for whom he coached under Rich Kotite.

Hamilton, who coached with Pete Carroll’s staff in New England before being released from the team on Monday, said he’s heard from Jet people that the Jets are interested in him but he’s yet to hear from Groh.